package com.travelsky.app.util.system;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.log4j.Logger;
import org.springframework.util.Assert;
/**
 * 
 * 项目名称：travelsky   
 * 类名称：ReqUtil   
 * 类描述： 处理Request和Session的辅助类  
 * 创建人：gchzhou gczhou@travelsky.com 
 * 创建时间：2011-5-20 下午01:10:56   
 * 修改人： gchzhou gczhou@travelsky.com
 * 修改时间：2011-5-20 下午01:10:56   
 * 修改备注：   
 * @version 1.0
 */
public class ReqUtil {
	private static final String STOWED_REQUEST_ATTRIBS = "ssl.redirect.attrib.stowed";

	private static Logger log = Logger.getLogger(ReqUtil.class.getName());
	/**
	 * Creates query String from request body parameters
	 */
	public static String getRequestParameters(HttpServletRequest aRequest) {
		Map m = aRequest.getParameterMap();

		return createQueryStringFromMap(m, "&").toString();
	}

	/**
	 * Builds a query string from a given map of parameters
	 * 
	 * @param m
	 *            A map of parameters
	 * @param ampersand
	 *            String to use for ampersands (e.g. "&" or "&amp;" )
	 * 
	 * @return query string (with no leading "?")
	 */
	public static StringBuffer createQueryStringFromMap(Map m, String ampersand) {
		StringBuffer aReturn = new StringBuffer("");
		Set aEntryS = m.entrySet();
		Iterator aEntryI = aEntryS.iterator();

		while (aEntryI.hasNext()) {
			Map.Entry aEntry = (Map.Entry) aEntryI.next();
			Object o = aEntry.getValue();

			if (o == null) {
				append(aEntry.getKey(), "", aReturn, ampersand);
			} else if (o instanceof String) {
				append(aEntry.getKey(), o, aReturn, ampersand);
			} else if (o instanceof String[]) {
				String[] aValues = (String[]) o;

				for (int i = 0; i < aValues.length; i++) {
					append(aEntry.getKey(), aValues[i], aReturn, ampersand);
				}
			} else {
				append(aEntry.getKey(), o, aReturn, ampersand);
			}
		}

		return aReturn;
	}

	/**
	 * Appends new key and value pair to query string
	 * 
	 * @param key
	 *            parameter name
	 * @param value
	 *            value of parameter
	 * @param queryString
	 *            existing query string
	 * @param ampersand
	 *            string to use for ampersand (e.g. "&" or "&amp;")
	 * 
	 * @return query string (with no leading "?")
	 */
	private static StringBuffer append(Object key, Object value,StringBuffer queryString, String ampersand) {
		if (queryString.length() > 0) {
			queryString.append(ampersand);
		} 
		try {
			queryString.append(URLEncoder.encode(key.toString(), "UTF-8"));
			queryString.append("=");
			queryString.append(URLEncoder.encode(value.toString(), "UTF-8"));
		} catch (UnsupportedEncodingException e) {
			// won't happen since we're hard-coding UTF-8
		}
		return queryString;
	}

	/**
	 * Stores request attributes in session
	 * 
	 * @param aRequest
	 *            the current request
	 */
	public static void stowRequestAttributes(HttpServletRequest aRequest) {
		if (aRequest.getSession().getAttribute(STOWED_REQUEST_ATTRIBS) != null) {
			return;
		} 
		Enumeration e = aRequest.getAttributeNames();
		Map map = new HashMap();

		while (e.hasMoreElements()) {
			String name = (String) e.nextElement();
			map.put(name, aRequest.getAttribute(name));
		} 
		aRequest.getSession().setAttribute(STOWED_REQUEST_ATTRIBS, map);
	}

	/**
	 * Returns request attributes from session to request
	 * 
	 * @param aRequest
	 *            DOCUMENT ME!
	 */
	public static void reclaimRequestAttributes(HttpServletRequest aRequest) {
		Map map = (Map) aRequest.getSession().getAttribute(
				STOWED_REQUEST_ATTRIBS);

		if (map == null) {
			return;
		}

		Iterator itr = map.keySet().iterator();

		while (itr.hasNext()) {
			String name = (String) itr.next();
			aRequest.setAttribute(name, map.get(name));
		}

		aRequest.getSession().removeAttribute(STOWED_REQUEST_ATTRIBS);
	}

	/**
	 * Convenience method to set a cookie
	 * 
	 * @param response
	 * @param name
	 * @param value
	 * @param path
	 */
	public static void setCookie(HttpServletResponse response, String name, String value, String path) {
		if (log.isDebugEnabled()) 
			log.debug("Setting cookie '" + name + "' on path '" + path + "'");
		Cookie cookie = new Cookie(name, value);
		cookie.setSecure(false);
		cookie.setPath(path);
		cookie.setMaxAge(3600 * 24 * 30); // 30 days
		response.addCookie(cookie);
	}

	/**
	 * Convenience method to set a cookie without path
	 * 
	 * @param response
	 * @param name
	 * @param value
	 * @param path
	 */
	public static void setCookie(HttpServletRequest req,HttpServletResponse res,String cookieName,String cookieValueType) {
		boolean overdue = true;
		for (int i = 0; i < req.getCookies().length; i++) {
			if (req.getCookies()[i].getName().equals(cookieName)) {
				req.getCookies()[i].setValue(cookieValueType);
				res.addCookie(req.getCookies()[i]);
				overdue = false;
				break;
			}
		}
		if (overdue) {
			Cookie cookie = new Cookie(cookieName, cookieValueType);
			cookie.setMaxAge(-1);
			res.addCookie(cookie);
		}
	} 

	/**
	 * Convenience method to get a cookie by name
	 * 
	 * @param request
	 *            the current request
	 * @param name
	 *            the name of the cookie to find
	 * 
	 * @return the cookie (if found), null if not found
	 */
	public static Cookie getCookie(HttpServletRequest request, String name) {
		Cookie[] cookies = request.getCookies();
		Cookie returnCookie = null;

		if (cookies == null) {
			return returnCookie;
		}

		for (int i = 0; i < cookies.length; i++) {
			Cookie thisCookie = cookies[i];

			if (thisCookie.getName().equals(name)) {
				// cookies with no value do me no good!
				if (!thisCookie.getValue().equals("")) {
					returnCookie = thisCookie;
					break;
				}
			}
		}
		return returnCookie;
	}

	/**
	 * Convenience method for deleting a cookie by name
	 * 
	 * @param response
	 *            the current web response
	 * @param cookie
	 *            the cookie to delete
	 * @param path
	 *            the path on which the cookie was set (i.e. /appfuse)
	 */
	public static void deleteCookie(HttpServletResponse response,Cookie cookie, String path) {
		// Delete the cookie by setting its maximum age to zero
		if (cookie != null) {
			cookie.setMaxAge(0);
			cookie.setPath(path);
			response.addCookie(cookie);
		}
	}

	/**
	 * Convenience method to get the application's URL based on request
	 * variables.
	 */
	public static String getAppURL(HttpServletRequest request) {
		StringBuffer url = new StringBuffer();
		int port = request.getServerPort();
		if (port < 0) {
			port = 80;
		}
		String scheme = request.getScheme();
		url.append(scheme);
		url.append("://");
		url.append(request.getServerName());
		if ((scheme.equals("http") && (port != 80)) || (scheme.equals("https") && (port != 443))) {
			url.append(':');
			url.append(port);
		}
		url.append(request.getContextPath());
		return url.toString();
	}

	
	public static int getInt(HttpSession session,String param){ 
		try {
			return Integer.parseInt(session.getAttribute(param).toString());			
		} catch (Exception e) { 
		}
		return 0;
	}
	
	public static String getLocale(HttpServletRequest req){
		String language = req.getLocale().getLanguage();
		return language;
	}

	/** 
	 * 从Request中获取数据【attribute或者paramter】
	 * @param request
	 * @param name
	 * @return
	 */
	public static Object getRequestAttrOrPara(HttpServletRequest request,String name) {
		Assert.notNull(request, "Request must not be null"); 
		Object retObj = request.getParameter(name);
		if (null == retObj)
			retObj = request.getAttribute(name);
		return retObj;
	} 
	/** 
	 * 从Session中获取数据【但session不存在时，不创建新的Session直接返回空】
	* @param request
	* @param name
	*/ 
	public static Object getSessionAttribute(HttpServletRequest request, String name) { 
		Assert.notNull(request, "Request must not be null"); 
		HttpSession session = request.getSession(false); 
		return (session != null ? session.getAttribute(name) : null); 
	}  	
}
